The SMBJ8.5CA from Bourns is a bi-directional transient voltage suppressor (TVS) diode designed to protect sensitive electronics from voltage transients induced by system level events such as lightning, electrostatic discharge (ESD), and electrical fast transients (EFT). It is part of the SMBJ series, which is tailored for surge and ESD protection applications, offering a working peak reverse voltage range from 5V up to 495V. This specific model, with an 8.5V standoff voltage, is capable of dissipating up to 600 watts of peak pulse power (with a 1ms pulse width), ensuring reliable protection against high energy transients.
The SMBJ8.5CA features a compact chip package in the DO-214AA (SMB) size format, making it suitable for high-density board layouts. It has a typical fast response time of less than 1.0 picosecond for unidirectional devices and less than 5.0 picoseconds for bi-directional devices from 0V to Minimum Breakdown Voltage, ensuring quick protection for sensitive circuits. The device is designed to be easy to handle with standard pick and place equipment, and its flat configuration minimizes roll away, facilitating easy assembly.
Diod
Transient Voltage Suppressor (TVS) diodes are semiconductor devices designed to provide immediate transient voltage protection for electronic circuits from voltage spikes and surges. They are vital in safeguarding sensitive components against electrical threats such as lightning strikes, electrostatic discharge (ESD), and switching transients. TVS diodes can rapidly clamp the transient voltage to a safe level before it can damage the protected circuit, then return to a non-conductive state once the overvoltage condition passes.
When selecting a TVS diode, engineers should consider parameters such as standoff voltage, peak pulse power dissipation, clamping voltage, and response time. The standoff voltage should be higher than the normal operating voltage of the circuit but lower than the voltage at which protection is needed. The peak pulse power dissipation indicates the maximum transient energy the diode can absorb without damage. The clamping voltage is the voltage level at which the diode begins to conduct significantly, limiting the voltage spike. Fast response time is crucial for effective protection against rapidly occurring transients.
TVS diodes are used in a wide range of applications, including communication lines, power supply circuits, and electronic devices, to prevent damage from voltage spikes and surges. They are available in unidirectional and bidirectional configurations, with the latter providing symmetrical protection in AC circuits or where the polarity of the transient could reverse.
Choosing the correct TVS diode involves understanding the specific requirements of the application, such as the maximum operating voltage, desired clamping voltage, and necessary power dissipation capacity. It's also important to consider the diode's package size and mounting type to ensure it fits within the device's design constraints.